add dns lookup test

test/IXDNSLookupTest.cpp

@@ -0,0 +1,50 @@
+/*
+ *  IXDNSLookupTest.cpp
+ *  Author: Benjamin Sergeant
+ *  Copyright (c) 2018 Machine Zone. All rights reserved.
+ */
+
+#include "catch.hpp"
+
+#include "IXTest.h"
+#include <ixwebsocket/IXDNSLookup.h>
+#include <iostream>
+
+using namespace ix;
+
+
+TEST_CASE("dns", "[net]")
+{
+    SECTION("Test resolving a known hostname")
+    {
+        DNSLookup dnsLookup("www.google.com", 80);
+
+        std::string errMsg;
+        struct addrinfo* res;
+
+        res = dnsLookup.resolve(errMsg, [] { return false; });
+        std::cerr << "Error message: " << errMsg << std::endl;
+        REQUIRE(res != nullptr);
+    }
+
+    SECTION("Test resolving a non-existing hostname")
+    {
+        DNSLookup dnsLookup("wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww", 80);
+
+        std::string errMsg;
+        struct addrinfo* res = dnsLookup.resolve(errMsg, [] { return false; });
+        std::cerr << "Error message: " << errMsg << std::endl;
+        REQUIRE(res == nullptr);
+    }
+
+    SECTION("Test resolving a good hostname, with cancellation")
+    {
+        DNSLookup dnsLookup("www.google.com", 80, 1);
+
+        std::string errMsg;
+        // The callback returning true means we are requesting cancellation
+        struct addrinfo* res = dnsLookup.resolve(errMsg, [] { return true; });
+        std::cerr << "Error message: " << errMsg << std::endl;
+        REQUIRE(res == nullptr);
+    }
+}